How warm is it in San Diego in August?

Daytime highs averaged 31.1 °C, night-time lows 18.4 °C. The highest value of the past 10 years was 37.8 °C (18 Aug 2020), the lowest 13.2 °C (15 Aug 2025).

How often does it rain in San Diego in August?

On average there were 1.8 rain days (at least 1 mm) with 9.7 mm of precipitation in total. In 2 of 10 years there was no rain day at all.

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San Diego weather in August: temperature & rain

Photo: Adbar · CC BY-SA 3.0

🇺🇸 Weather in San Diego in August

This is what the weather in San Diego (California, USA) was like in August over the years 2017–2026.

Key facts at a glance

Prevailing weather: Cloudy

Avg. daytime high

31.1 °C

30.5 °C – 32.2 °C

Avg. night-time low

18.4 °C

17.2 °C – 20.0 °C

Avg. rain days in period

1.8

6 % of days · ≥ 1.0 mm

Avg. precipitation in period

9.7 mm

0.2 mm – 47.4 mm

Avg. cloud cover

64 %

This data source has no sunshine hours – average cloud cover is shown instead.

Avg. sea temperature

–

Sea temperature unavailable for today (daily limit).

Extremes: Highest temperature 37.8 °C (18 Aug 2020) · Lowest temperature 13.2 °C (15 Aug 2025) · Avg. daily peak wind 18 km/h

Weather mix of all days

32Sunny
111Partly cloudy
119Cloudy
16Light rain
2Rain

Summary

On average 31.1 °C during the day and 18.4 °C at night.
On average 1.8 rain days (Rain day = at least 1.0 mm of precipitation) with 9.7 mm of precipitation in total.
In 2 of 10 years there was not a single rain day.
Prevailing weather: Cloudy.
Warmest year: 2026 (avg. 32.2 °C), coolest: 2023 (avg. 30.5 °C).
Wettest year: 2023 (47.4 mm), driest: 2020 (0.2 mm).
Extremes: 37.8 °C on 18 Aug 2020 and 13.2 °C on 15 Aug 2025.

Overall values from all 10 years. How is this calculated?

Temperatures per year

Average over your travel period

Precipitation & rain days

Year by year

2026
Avg. max32.2°Avg. min20.0°
Rain days
1 Rain days
Precipitation
7.3 mm
Avg. cloud cover
–
Sea temperature
–
Max 36.1 °C · Min 17.2 °C
2025
Avg. max30.7°Avg. min17.7°
Rain days
3 Rain days
Precipitation
11.8 mm
Avg. cloud cover
64 % cloudy
Sea temperature
–
Max 34.4 °C · Min 13.2 °C
2024
Avg. max31.1°Avg. min18.1°
Rain days
2 Rain days
Precipitation
4.2 mm
Avg. cloud cover
53 % cloudy
Sea temperature
–
Max 35.6 °C · Min 14.3 °C
2023
Avg. max30.5°Avg. min18.2°
Rain days
1 Rain days
Precipitation
47.4 mm
Avg. cloud cover
61 % cloudy
Sea temperature
–
Max 34.7 °C · Min 14.2 °C
2022
Avg. max32.1°Avg. min19.5°
Rain days
4 Rain days
Precipitation
7.1 mm
Avg. cloud cover
57 % cloudy
Sea temperature
–
Max 37.8 °C · Min 16.7 °C
2021
Avg. max30.6°Avg. min18.2°
Rain days
2 Rain days
Precipitation
5.0 mm
Avg. cloud cover
61 % cloudy
Sea temperature
–
Max 34.4 °C · Min 14.3 °C
2020
Avg. max31.0°Avg. min18.6°
Rain days
0 Rain days
Precipitation
0.2 mm
Avg. cloud cover
61 % cloudy
Sea temperature
–
Max 37.8 °C · Min 13.5 °C
2019
Avg. max30.8°Avg. min17.2°
Rain days
0 Rain days
Precipitation
0.9 mm
Avg. cloud cover
76 % cloudy
Sea temperature
–
Max 34.6 °C · Min 13.3 °C
2018
Avg. max31.3°Avg. min19.0°
Rain days
2 Rain days
Precipitation
5.3 mm
Avg. cloud cover
60 % cloudy
Sea temperature
–
Max 36.1 °C · Min 15.1 °C
2017
Avg. max30.7°Avg. min17.8°
Rain days
3 Rain days
Precipitation
7.9 mm
Avg. cloud cover
79 % cloudy
Sea temperature
–
Max 36.4 °C · Min 13.7 °C

Frequently asked questions

How warm is it in San Diego in August?: Daytime highs averaged 31.1 °C, night-time lows 18.4 °C. The highest value of the past 10 years was 37.8 °C (18 Aug 2020), the lowest 13.2 °C (15 Aug 2025).
How often does it rain in San Diego in August?: On average there were 1.8 rain days (at least 1 mm) with 9.7 mm of precipitation in total. In 2 of 10 years there was no rain day at all.

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Data sources

Weather data: Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. Snow depth is the model value for the grid cell, not the depth on the slopes. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains.
Sea temperature: MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis)
Place search: Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)